AS THE Mets and Yankees move rapidly toward October, two of their promising young relievers, Henry Owens and J. Brent Cox, are having a major impact on Davey Johnson’s Team USA.

The experience of playing in Cuba in the 2006 Americas Olympic Qualifying Tournament, and making the field for the 2008 Beijing Olympics, has opened their eyes to another world.

“This has been unbelievable,” Cox, the Yankees’ second-round pick of the 2005 draft out of the University of Texas, said by phone from Havana, where the U.S. team is 5-1 and will meet undefeated Cuba in the championship game today. Team USA’s 11-5 win over Panama on Sunday put them in the Olympics. Both Cuba and the U.S. have qualified.

“Playing for your country and playing with some of the best players in your country is incredible; we really want to win this thing,” added Cox, 22, who has had two solid relief appearances.

“Coming in here,” said Owens, 27, “I didn’t know what to expect, but our team has really meshed nicely.”

For Owens, selected by the Mets in the 2004 Rule V draft, this tournament is about coming home. His mother, Mini, left Cuba at the age of seven with her family to escape Fidel Castro.

“This has been one of the most memorable experiences of my life,” explained Owens, who lives in Miami. The blazing right-hander pitched well in his first three outings, picking up one save.

“I’m appreciating everything I’m seeing, and taking my camera everywhere,” Owens added. “I’m even working on my salsa dancing. . . . I have Cuban blood inside me and I just needed to see where my mom was born and where a part of me is from.

“When I start speaking Spanish, the fans love that, in fact they’ve asked me to come play for the local team here.”

Unlike their major league counterparts, there have been no creature comforts in Cuba, unless you count the creature (some type of insect) that gave coach Reggie Smith some nasty bites in the team’s first hotel.

That hotel was a disaster. Mattresses sat directly on the floor. There were no toilet seats, no carpeting, no air conditioning, no phones or Internet access. There was one working elevator. That was good, considering players and team officials were housed on the 21st floor and above. Bob Watson, GM for USA Baseball, was awakened one night by cats fighting in the hallway outside his room.

“All that has managed to bring us together,” said Cox.

The club has since upgraded to the Havana Libre hotel, which isn’t exactly the Four Seasons, but does have ESPN.

The players love seeing the classic old cars throughout Havana.

“They’re from the 50s and 60s; it’s pretty crazy that they’re still working,” Cox said. “We’ve all been getting our picture taken with them.”

The people of Cuba have had the biggest impact on the players.

“They love the game more than anything,” Cox said. “They’re so friendly. They cheer for good baseball. But it’s kind of sad to see the kids and what they don’t have, so we’re trying to help them out as much as possible and show them a good time. They love talking to us and they know all the big leaguers.”

Owens noted: “The kids have such a passion for baseball. Anytime we have a chance to do something nice for them, we do, whether that’s giving them food or equipment or slipping them a few dollars. What they really want though is baseballs.”

The ballplayers are giving the youngsters the gift of America’s Game.

“You don’t think twice about giving them anything you have,” Owens added. “I brought a good amount of money with me and I really don’t plan on coming home with much of it. The people here need it so much more.”